Improvement in boot and shoe sewing machines



' I L. RMBLAKE.

, Boot and Shoe Sewing-Machined No. 207,340 Patented Aug. 27,1878.

UNITED ST TES. PATENT Grimes.

LYMAN lt. BLAKE, 01 BOSTON, MASSACHUSETTS;

IMPROVEMENT LIN BOOT AND SHOE SEWlNG MACHINES.

Specification Forming partof Letters Patent No. 207,34), dated August27', 1378,- application filed J une 6, L377.

To all whom it may concern Be it known that I, LYMAN l. RLAKE, ofBoston, in the county 01. Sultolk and State of Massachusetts, haveinvented an Improvementin Sewing-Machines, of which the follow ing is aspecification:

.This invention. relates to sewing-machines chiefly designed to sewsoles to uppersin the manufacture of boots and shocs,'and is'auimprovement upon the machines represented in United States lateuts Nos.36,163 and 45,422.

In the present machine many of the parts operate described in the saidpatents, and need not therefore be specifically described.

Instead of operating the presser as in such patented machines, it timedwith reference to the movement of the needle, so that the stock is helddown-upon the horn: until the needle eomplctesthat portion of its upwardincrement derived from the action of the neodle-bar-actuating lever andits operating-earn, such movement drawing up and completing the stitch,and then the presser is lifted while the stock is fed the necessarydistance for another stitch. In this way the sole and upper are heldclamped together between the presser and horn when the stitch is drawntaut, the stock being thereby held more firmly and closely/together atthe stitch'making point than would be possible were the thread alonedepenih'rd} upon, as heretofore.

1n the "McKay i'nachine, as now made, the presser is raised just aboutas the book of the needle in its ascent reaches and commences to drawthe threadthrough the inner sole. This :upward movement of the prcsserreleases the stock from pressure between it and the horn,

and the force ivit-lrwhich the contacting faces of the stock is(:IObidediu pressed-togetheris made dependent on thethrcad alone.

The thread resting in the hook of the needle is usually subjected to allthe strain that it will bear without breaking, This strain averages fromseventy to ninety pounds, but in actual work the stock is not reallydrawn together with a force equal to the strength of the tl ircad, formuch of. the strength of the waxed 'thread is consun'ied by frictionabout, the stock and by reason oi. its being frayed and eha-ted bystraining it about the hook of-the needle.

I have found that the ripping of machinesewcd shoes is due to thel'actthat the stitches are cut at the junction of the sole and upper, byreason of the movement of the outer sole longitudinally with referenceto the face of the upperplaeed between it and t-heinuersole. The

solo, in ordinary use, is never pulled from bolts of thread attached tothe inner sole or upper,

as would be the case if the outer sole became loose by reason of cuttingthe thread at the outer face of the outer sole. r

I have demonstrated that the thread holding the upper and outsolotogether is cut by the-longitudinal movement of the sole over allstrain, except that resulting from friction A between itselfand thehole-madefor it in the stock, and, being drawn closely up to and upon.

the stock held as v before described, the stock I is retained by thethread in substantially the position at which it was held between thepresser and horn, so that thesole or parts thereof outside the upperwill not move longitudinally over the face of the portion of the upperbetween the outer and inner'soles, and

consequently the stitches-will not be out. :In

sewing in this way, the thread having beenrelicyed from most of itsstrain, another most important result is aeoomplished-viz., the holes inthe stock are better and-more completelyfilled with thread. If thestrainon the thread is notcons ume-d in crowding the stock together, then thethread may be largeiyas compared with the needle-hole, without fear ofbreaking it when bein g drawn therethrouglu Either the needle may bemade smaller with the same size thread, or with a needle of usual size alarger thread may be used. This 1ncrease ol' thread in the needle-holesadds very 1 materiallyto the strengthand durability of the shoe, as willbe apparent to those skilled in the art. t

The presser,restiug in the channel of theouter solejust at or justinadvanee ot' the stitch-making point, holds the stock together firmlyand closely by the action, in this instance, of a strong-spiral spring,made adjustable, so as to exert a certain minimum amount of pressurewhile the hook of the needle is below the stock; and as the hook of theneedle, in rising with the loop, meets the stock and begins to exert anupward pull thereon, then the force required to draw the needle and loopthrough the stock is transferred to the presser through the action of apressure-augmenting lever, one end of which is fixed in position, whilethe other end rests upon a lug projecting from the presser-bar. An armfrom the needle-lever fulcrum rests upon this augmenting-lever, and isprovided with an adjustingscrew to insure a loop of the proper length,-and thereafter thislength of loop is maintained, notwithstandingvariation in the thickness of the stock.

Figure 1 represents, in front elevation, theupper part or head of asole-sewing machine provided with my invention; Fig. 2, a side viewthereof; Fig. 3, a detail of the fulcrum for the presser-lifter, andFig; 4 a detail of the 2am for operating and changing the length ofe'ed.

ating mechanism. 1 The presser, its carryingbar h, provided with ascrew-thread, theratchetwheel y thereon, the pawls 2 2 and devices tooperate them, spring j,c-needle-lever, its movable fulcrum-bar k,needle-bar l, and feeder are in construction substantially asvin PatentNo.

45,422, before referred to; but their "times of movement and operationupon the stock in --the process of making the, shoe are varied for thepurposes herein described, to produce more solid work, which will notrip.

The cast-oif 3, connected with the cast-off bar 5, operates with theneedle 4 to cover and uncover its hook, as usual. A lug, 6, at the upperend of the cast-off bar,'receives through it a rod, m. An adjustablestop secured to the lower end of the rod m bears against the under sideof the lug 6, and a spiral spring, 8, on the rod rests upon the top ofthe lug to permit the cast-oil to be moved down under a yieldingpressure.

Aproje'cting collar, 10, on the needle-bar meets, at its ascent anddescent, adjustable stops 9 attached to the rod m, so as to raise I andlower it at the proper time to uncover and cover the hook of the needle.The rod m is held, when the needle-bar changes its direction ofmovement, bya friction device, a; The needle-lever is connected by alink, p, with a collar, g, on the needle-bar.

The arm 1, adjustably connected with the movable fulcrum-post of theneedle-lever by a screw, 11, has its free end extended laterally, so asto rest upon the pressure-angmcnting lever s. This lover 8 hours at itsrear end 13 on the plate 1, instead of upon a projection The main shafta of the machine is'provided from the rising-a-nd-falling fulcrum-rod ofthe presser-lifting lever, as heretofore common.

and its forward end rests,,in this instance, in

a slot in an ear, 15, forming part of the risingand-falling stock of thepresser. The arm r has an adjusting-screw, a, which may be adjusted to.regulate the length of loop to be drawn above the stock, and thereafterthe same length of .loop is maintained automatically with allthicknesses of stock.

In the old machine, the length of loop was ed by moving the barr up ordown upon the heedle fulcrum-post, which was diflicult' chang when itwas desired to make but a slight variation in the length of loop,because the setscrew would slip into the depression made by the screwwhen previously set tight.

The end of the screw it will, in practice, rest upon a shoe, 8, as shownin Fig. 2, the shoe preventing the screw from wearing into the lever. IThe presser-liftin g lever 10 is connectedin the ordinary way with theblock m, which carries the ratchet 3 that surrounds the screwt-hreadedportion 'of the presser-shank It. The lever to has its fulcrum in a box,16, pivoted on the turned-down ends 18 of screws 17, ex'- tended throughears of a depending stand, 19, made horizontally adjustable in a slot,20, of the plate 21, so as to vary the length'of the lever and the liftof the presser. A gib, 22, in the box 16 is pressed against the lowerend of the lever w by a screw, 23.

The presser-foot may be lifted more or less at each rotation of the camb by adjusting the fulcrum of the lever to. i

' In the ordinary McKay machine the pre'sserlifting lever has itsfulcrum on a rising andfalling fulcrum-post. This is objectionable; forwhen the fulcrum-post is permitted to rise more or less, so as to varythe lift of the presser, the end of the lever is changed in position, sothat they cam operates it out of time with relation to the feed.

In the present machine the length' of the feed may be changed atpleasure by moving the throwing part 24 of the feed-cam d, such part 24being adjustably connected with such cam'by screws 25, placed inelongated slots in the throwing part. I

In the usual McKay machine it is necessary to shift the'feed-operatingcam longitudinally on its shaft to lengthen the feed-stroke. Thismovement of the cam so changes its relation with the fulcrum of an armin all respects like that herein marked 9 that the feed-point, as

it is depressed, is thrown a little forward out of time. 7

In this invention the lateral movement of the feed is produced withoutshiftin g the cam on the shaft, and. consequently the stock is notpulled when the presser holds it down, as it would beif the feed, as itdescended, moved forward just in advance of its time.

The rocking motion of the shaft 26, moved by the cam (l and arm f,o'pcrates thc feeding dog 27 in the ordinarymanner. The rotating I horn28 will be as in the patents referred to.

The usual whirl-in the horn will preferably be operated Continuously inone direction, but at a variable speed, by devices such as shown inanother application filed by-me June 6, 1877, for Letters Patent, suchwhirl being operated throughthe agency of eccentric-gears, so as to giveit a fast and slow motion.

The drawing shows two pieces of leather,

' 29 30, between the presser and horn. It will be assumed that the piece29 represents the outersole and the piece 30'the upper, they beingplaced in contact in any of the ways in which such parts are placedtogether to be united on the McKay maehine, and that the presser restsina channel cut in the sole in any usual way. t i

Inthe drawing the needle is represented as having reached its topstroke, where the loop of thread is drawn closely and firmly up into thestock,'and it has there rested sufficiently .long to permit the feed toengage the stock.

and to permit the pawlsto lock into the ratchet y, so that theresser-foot maybe lifted, whereas in the old machine the ratchet islooked just 'lS the needle commences to rise.

that one stitch has-been made, then when the needle commences to descendfrom its highest Assuming position the presser rests with its lower endin the channel in the outer sole just at or near the point at which theneedle is about to enter the stock. The presser is held down by thestress of the springj. The loop of thread just drawn into and throughthe stock, just beyond the end of the presser, holds the stock' togetherat that point firmly. 'The needle penetrates the stock and enters-thehole in the horn, and thewhirl lays a thread into the heck of theneedle, and then the needle is raised. As the needle commences to risethe needle-lever is called upon to exert sufficient power to draw theloop and hook up through The power required to the hole in the SCOCK- dothis is exerted by the needle-lever, and the force expended at the outerend of such lever is made to depress the fulcrum-post. of theneedle-leverwith an equal amount offorcc,

and such post, through the arm 1*, resting on the augmenting-lever .9,connected with the presser, causes the strain required to draw theneedle and loop up through the stock to be transferred at each stitch tothe presscr-ibot, thereby increasing the pressure of the presser upontheystock at'each stitch over and beyond the pressure of the spring,this amount of increase of pressure varying according to the thicknessand density of the stock.

The thread, as heretofore used in the McKay machine,'has crowded thestock together at the stitch-making point with a force equal to thestrengtlr of the thread employed less its lossoi' strength by reason offriction on the stock and abrasion on the hook of the needie. Themaximum pressure exerted by such thread is many times less than thepressure exerted by the presser in the present inven- -loop up throughthe hole and the tion. This presser holds the stock crowded closelytogether until the needle draws the stock, and thereby confines thestock in the condition in,

which it was held by the presser and horn.

After the stitch is drawn up the feedpoint 27 descends and penetratesthe stock. The presser-foot is then lifted posit-ivelyjnst cnou gh topermit the stock to be moved over thehorn, and'then the feed-point ismoved laterally to feed the stock for a new stitch. The needle, throughparts s r k f p I, was lifted a little as the presser was lifted. Suchmovement did not farther draw the loop into the stock, but simply heldit taut. After the completion of the feed the presser is again allowedto dc seend upon and clamp and hold the steel; 'until the thread isagain drawn through it.

In the old form of machine them-creased strain upon the needlefulcrum-post, caused by drawing the loop through the stock, was notpermitted to increase the pressure of the presser on the stock, for atthat time the p'awls were thrown into engagement with the ratchet, andthe presser-loot was lifted from the horn.

The pressure-oi the presser-foot upon the stock has been described asvariable at each stitch. This is the way it is preferred to com streetthe machine; but instead of such construet-ion the presser may be helddown by the stress of a spring and be lifted from eontact with thestock, as and in accordance with the time just before described.

In ordinary sewing, the thread, as the stitch is drawn taut, acts togive the final set to the material being sewed together.

In this my machine the presser-ibot in the channel is caused to pressthe stock together in the exact line of the seam, and the pressure soexerted is always inexcessof thepressure which the thread can exert, andconsequently the stitch, when drawn taut, doesnot give to the stock itsfinal set.

I claim-- 1. In a solc-sewingmachine,the presser and the ncedleactuatinglever and its movable fulcrum-post, in combination with connectingmechanism whereby the resistance which the needle and thread meet within being drawn up through the stock is transferred. to the presserfootresting thereon to ii'ierease its pressure at each stitch, substantiallyas described.

2. The combination, with the needle, the presser'i'oot, its spring,ratchet, and ratchetholding pawl, of mechanism tolock the ratchet andpermit the presserfoot to be lifted from pressure on thc'stoclc just asthe needle completes the stitch, as and for the purpose described.

3; The combination, with. the needle-lever, fulcrum-post, and its arm,of the screw it, to adjust the length ot'loop, substanLially asdescribed.

4. The presser-i'oot-lifiing lever, in eombi.

'nation with the pivoted horizohtally-adjust- In testimony whereof Ihave signed my able fulcrum-block to operate substantially name to thisspecification in the presence of I a-nism, its connected shaft 26, andarm g, of

two subscribing witnesses.

LYMAN B. BLAKE.

as described.

5. The combination, with the feeding mechthe cam 61 and its adjlist-able throwin part 24, Vitnesses:

to vary. the length of feed, substantiifil y as de- G. \V. GREGORY,scribed. V. J. PRATT.

